Sheet feeding machine



SHEET FEEDING MACHINE Aug. 14, 1962 7 Sheets-Sheet 1 Filed Oct. 1, 1958 I I I JZ f 0? 50 INVENTOR.

Aug. 14, 1962 F. DUSSART 3,049,347

SHEET FEEDING MACHINE Filed Oct. 1, 1958 I 7 Sheets-Sheet 2 INVENTOR. 22 if FPma /m 4am QVJS/MT lax AGE/V7 Aug. 14, 1962 F. DUSSART 3,049,347

SHEET FEEDING MACHINE Filed Oct. 1, 1958 '7 Sheets-Sheet 3 fig. 3

IN VEN TOR.

FEEDER/(k ZEW/S Duff/4E7 BY 250 2 Aug. 14, 1962 F. L. DUSSART 3,049,347

SHEET FEEDING MACHINE Filed Oct. 1, 1958 7 Sheets-Sheet 5 Q J M )Q R Q INVENTOR. cg M FPfflfP/(X LEW/5 0055/45?" g BY 4&7) .Q

AGE/VT Aug. 14, 1962 F. L. DUSSART SHEET FEEDING MACHINE 7 Sheets-Sheet 7 Filed Oct. 1, 1958 ij ik fl #NEM NNTQ United States ,Ofiice.

3,049,347 Patented Aug. 14, I962 3,049,347 SHEET FEEDING MACHINE Frederick Lewis Dussart, Oakland, Calif., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Oct. 1, 1958, Ser. No. 764,659 7 Claims. (Cl. 271-8) The present invention relates to sheet feeding machines, and more particularly to devices for preventing the interlocking of the scroll cut lateral edges of sheets as they are fed from a stack.

One of the recent developments in the can manufacturing industry has been the adoption of the use of sheets having at least two opposed scroll cut edges such as are produced by the invention disclosed in Carl G. Preis Patent 2,234,195 issued March 11, 194-1 and entitled Method of Manufacturing Tin Plate." Such sheets are usually cut from strip stock and piled into a stack to facilitate storage and handling.

When the sheets are subsequently used in can manufacture, the stack is placed in the magazine of a sheet feeding device which feeds the sheets from the top of the stack into treating machines such as coaters or scroll shear presses. In the sheet feeding machine, the upperpost sheet is usually grasped by suction cups and lifted vertically away from the stack in order to insure separation from the next lowermost sheet and to raise it to the feed line. The suction cups are then swung in a for- Ward direction to move the sheet horizontally into the bite of feed rolls which feed it onto the feed table of the treating machine. The suction cups have only a short forward stroke and release their grip upon the sheet as soon as it is grasped by the feed rolls. Thus, for the greater portion of its horizontal movement across the top of the stack, the sheet is unsupported.

Since the sheet is made of comparatively thin stock, it has a tendency to sag into contact with and slide along the upper surface of the sheet immediately below it during the greater portion of this horizontal movement. When the sheets being fed are provided with straight lateral edges, this sliding contact between the sheets is unobjectionable. However, when the lateral edges of the sheets are provided with undulating scroll cuts which create alternate recesses and tabs in the sheet edges, it has been found that the tabs on the contacting sheets have a tendency to interlock with the result that the sheet which is being fed horizontally hooks onto the sheet immediately below it and drags it from the stack, thus jamming the machine and causing wrecks which necessitate shutting down of the machine until it can be cleared and, if necessary, repaired. It is not possible to operate commercially under such conditions, since there is a great loss of productive efliciency.

In order to overcome this tendency of the sheets to interlock, the present invention contemplates the provision of anti-hooking devices which support the lateral edges of the horizontally moving sheet and thus maintain its tabs out of contact with the tabs of the sheet immediately below it. In their most desirable form, these devices comprise movable flapper fingers which rest upon the tabs of the topmost sheet in the stack and move upwardly with the sheet as it is raised vertically by the suction cups. When this topmost sheet is then moved horizontally over the top of the stack, the forward ends of these flappers ride off its tabs and drop onto the corresponding tabs of the next sheet in the stack. As a result, these flappers become interposed between the tabs of the topmost sheet and those of the sheet immediately below it, and thus function to keep these tabs separated from each other, thereby obviating the possibility of their hooking together. This action .is repeated for each sheet, and it has been 2 found that these flappers are completely effective in eliminating the interlocking of sheets in the sheet feeding machine.

An object of the invention therefore is the provision in amachine for feeding scrolled edge sheets of simple mechanical devices which completely overcome the tendency of such sheets to become interlocked during the feeding operation.

Another object is the provision of such mechanical devices which are simple in construction and which may be easily mounted in the magazine of the sheet feeder and are always in eifective operating position.

A still further object is the provision of simple light weight mechanical anti-interlocking devices which operate freely in response to the movement of the sheets without scratching or otherwise damaging their surfaces.

Yet another object is the provision of devices which provide low friction support surfaces at or just below the feed line of a sheet feeding machine to support the lateral edges of the sheet being fed therefrom.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof. 1

Referring to the drawings:

FIGURE 1 is a plan view of a sheet feeding apparatus embodying the instant invention and showing'in dot and dash lines the position of a stack of scroll edged sheets in feeding position;

FIG. 2 is a side elevation of the apparatus illustrated in FIG. 1, as viewed from the left hand side of that figure;

- FIG. 3 is a rear view of the apparatus illustrated in FIG. 1;

FIG. 4 is a vertical section taken substantially along the line 44 in FIG. 1, parts being broken away;

FIG. 5 is a side elevation of a portion of the mecha-" nism-of FIG. 4 as viewed from the right hand side of that figure, parts being broken away;

FIGS. 6 and 7 are enlarged plan views of a lateral portion of the machine duringsuccessive stages of the feed-. ing operation and illustrating the positionalrelationship between the scroll cut lateral edges of the sheets in the stack and the flapper fingers which prevent interlocking of the sheets;

FIG. 8 is a vertical sectional view taken substantially along theline '88 in FIG. 6 showing the stack of sheets being moved upwardly by the elevator platform into. feeding position with the top of the stack just about to enter the zone of magnetic separation, parts beingbroken away;

FIGS. -9 and 10 are views similar to FIG. 8 but showingsuccessive stages of the sheet feeding operation, FIG. 9 showing the sheets in the top of the stack magneticallyseparated but prior to the downward movement of the suc-- tion cups, and FIG. 10 showing the topmost sheet in the stack raised to the feed line by the suction cups;

FIG. 11 is a vertical sectional view taken substantially. along the line.1'l1=1 in FIG. 7 and showing a stage in the feeding operation subsequent to that shown in FIG.- 10, parts being broken away; and I FIG; 12 is a view similar to FIG. 11 showing a still, later stage in the feeding operation.

As a, preferred or exemplary embodiment of the invention, the drawings illustrate a sheet feeding machine adapted to feed individual sheets stack B which is preferably supported on a wooden skid C which may be inserted in the A machine by means of a lift truck in the usual manner.- The lateral edges of each sheet A are scroll cut in a scroll pattern which-provides alternating tabs T and recessesR, as best seen in FIG. 1. Y

The machine is basically of the type illustrated in L.

A from the top ofxafeed magazine of the Baker et al. Patent 2,156,648, issued May 2, 1939 and entitled Sheet Feeder, and includes a main frame formed of four corner uprights 20 which are provided at their lower ends with angle irons 22 which are bolted to the floor or platform on which the machine is mounted (not shown). The uprights 20 are tied together by a front rod 24 and a rear rod 26 and by a non-magnetic frame comprising two side bars 28, a front bar 30 and a rear bar 32 which is connected to the rear uprights through a pair of short extension bars 34.

The skid C which holds the stack B is received on an elevator platform 40 which is provided with a pair of spaced channel irons 42 in which are carried antifriction rollers 44 which contact the bottom of the skid C. These rollers 44 permit manual adjustment of the stack into the desired unstacking position with its front edge in contact with a pair of vertical guide bars 46 which are secured adjacent their upper ends to a crossbar 48 by means of connecting Z-bars 50. At their lower ends, the vertical guide bars 46 are provided with irons 52 which are bolted to the machine platform.

The elevator platform 40 is elevated in synchronism with the removal of sheets from the top of the stack in order to maintain the top level of the stack by means of elevating devices which are shown in detail in H. W. Lindgren Patent 2,375,241, issued May 8, 1945 and entitled Sheet Stacking Machine. Such devices include four vertical chains 56 (see FIGS. 1-3), one of which is secured to each corner of the platform 40 by means of bolts 58, The chains 56 operate around sprockets 60 which are keyed to sprocket shafts 62, 64 which are journalled in bearings mounted in the frame uprights 20. The shaft 62 is rotated by suitable driving mechanism (not shown), as required to raise or lower the platform 40, through the medium of a worm gear 66 which is keyed to the shaft 62. The rotation of shaft 62 is transmitted to shaft 64 by means of a cross-shaft 70 which carries a small worm gear 72 at each end, one of the gears 72 meshing with the large Worm gear 66 and the other nesting with a similar large worm gear 74 keyed to the sprocket shaft 64.

In order to prevent the feeding of doubles, the sheets in the upper end of the stack B are preliminarily separated from each other in a manner similar to that described in detail in Robert T. Chatterton Patent 2,474,- 141, issued on June 21, 1949' and entitled Method and Apparatus for Feeding Sheets.

To accomplish this, three elongated electromagnetic pole piece units 80, 82 and 84 are provided, the pole piece units 80 and 82 being of like polarity and positioned along the lateral edges of the stack B and the pole piece unit 84 being of opposite polarity and positioned adjacent the rear edge of the stack B as best seen in FIG. 1. The pole piece units 80, 82 and 84 are secured to the lower ends of core pieces 86 which in turn depend from slides 88 which are adjustably mounted on a T-yoke comprising a cross-plate 90, secured to the side bars 28, and a tail plate 92 which is secured at one end to the cross-plate 90 and at the other end to an angle iron 95 secured to the rear bar 32.

Each pole piece unit comprises an elongated magnetizable pole piece 94 (see FIG. 4) and nonmagnetic guide pieces 96, 98, and is faced with nonmagnetic spacer plates 102, 104. The pole piece units are energized by suitable coils 106 which are carried by the core pieces 86.

When the stack is first positioned on the platform 40, the elevator mechanism is actuated to raise the platform to bring the upper edge of the stack within the magnetic field or zone of separation created by the pole piece units 80, 82 and 84. FIGURE 8 shows the stack moving upwardly, just prior to the time it enters the magnetic field. This magnetic field saturates the sheets within it and causes them to repel each other, thus positively spacing them apart. As a result, the sheets in the upper portion of the stack float in vertically spaced relationship in the 4 magnetic field (as best seen in FIG. 9) with the topmost sheet located at a substantially predetermined pre-feed level.

When the topmost sheet is thus magnetically separated, it is ready to be removed from the stack. For this purpose two sets of suction cups are provided. The suction cups 110 of the first set are disposed above the forward edge of the sheet, while the suction cups 112 of the second set are positioned above its rear edge. As seen in FIG. 9, these suction cups 110, 112 are carried on the lower ends of vertical vacuum pipes 114 and are normally positioned with their lower surfaces at the feed line of the machine, which feed line is indicated by the dot and dash lines in FIGS. 8-10.

The cups 110, 1 12 are moved downwardly into contact with the topmost sheet in the magnetic field and are then raised in unison to further space the topmost sheet vertically from the sheet immediately below it and lift it to the feed line of the machine, as seen in FIG. 10. At this time, the front set of suction cups 110 is moved forward to carry the sheet along the feed line and deliver its leading edge into the bite of two spaced sets of feed rollers 116 which are secured on horizontal shafts 118 suitably mounted in the machine and continuously rotated in any suitable manner to continue the horizontal movement of the sheet and remove it from the machine. Suitable vacuum valves (not shown) are provided to cut off the vacuum in the cups 110 as soon as the feed rolls 116 gain control of the sheet, and the cups 110 are then returned to their normal position for the next feeding operation.

The rear set of suction cups 112 is preferably not horizontally movable as are the front suction cups 110 and are thus designed to release their hold upon the sheet just prior to the time the front suction cups begin to move toward the feed rollers 116. Upon release of the rear suction cups 116, the rear portion of the sheet begins to sag under the influence of gravity, as shown in FIG. 11.

In order to prevent the tabs T of the sagging sheet from coming into contact with the tabs T of the sheet immediately below it as it is fed horizontally from the machine by the suction cups 110 and feed rolls 116, and thus obviate any possibility of the tabs from becoming locked or hooked together, a plurality of separator or support members 120 are provided on each side of the stack B. As best seen in FIG. 1, a separator member 120 is positioned to the rear of each sheet tab T except the two rear tabs, at which latter positions separator members are not needed.

These separator members 120 are preferably nonmagnetic and comprise gently upwardly arched or curved flapper fingers 122 (see FIGS. 4 and 5) the rear portions of which are secured to hollow sleeve bearings 124 which are pivotally mounted on stationary pins 126 secured in the lateral pole piece units 80, 82 adjacent the top of the stack B in vertical alignment with the vertical grooves formed in the lateral edges of the stack B by the vertically aligned recesses R of the sheets A.

To facilitate removal or replacement of the separator members 120, each lateral pole piece unit is provided with a removable elongated slide bar 128 in which the pins 126 are secured. By this means, the separator members 120 on each of the units can be removed or adjusted relative to the stack B as a unit. The slide bars 128 are magnetic and are locked in place by set screws 130. If desired, each separator member could be mounted on a short, separate slide bar section to permit adjustment relative to each other.

The arcuate front portion of each flapper finger 122 projects forwardly so that its tip rests upon the immediately preceding tab T of the topmost magnetically separated sheet A in the stack B, as best seen in FIGS. 6 and 9. This contact remains while the sheet is lifted upwardly to the feed line by the suction cups 110, 112

(see FIG. the pivotal mounting of the fingers enabling them to move upwardly with the sheet without flexing and without scratching or otherwise damaging the sheet surface, but the forward horizontal movement of the sheet effected by the forward motion of the suction cups 110 slides the tabs T of the topmost sheet from beneath the flapper fingers 122 and permits the fingers to pivot downwardly by gravity onto the tabs T of the next topmost sheet immediately below, as seen in FIGS. 7 and 11. In this position, the gently rounded forward portions of the fingers 122 are raised slightly above the top surface of this next topmost sheet, and are interposed between the tabs T of this sheet and those of the horizontally moving topmost sheet, while the rear ends of the fingers 122 extend below the tabs T of the next topmost sheet. As a result, when the moving tabs T of the sagging topmost sheet are slid successively across the stationary tabs T of this next topmost sheet, they are engaged and are deflected upwardly by the interposed fingers 122 and are thus supported out of engagement with this next topmost sheet. Thus, interlocking of the tabs T of these sheets is positively prevented. Because of the smooth gentle curvature of the fingers 122, this deflection is effected gently and without damage to the tabs.

The enlarged head of each pin 126 carries a stop pin 132 which functions to limit the pivotal motion of its associated flapper finger 122 in both directions. As seen in FIG. 8, these pins 132 hold the fingers 122 in substantially horizontal position in the event there are no sheets A at the usual feeding level. In this position, the fingers automatically contact the topmost sheet when it is moved upwardly to the normal feeding level. Thus, the introduction of a new stack into the machine is greatly facilitated.

It is obvious that the present invention will effectively prevent interlocking of the sheet tabs T even if the preliminary magnetic separation of the sheets is omitted and the sheets lifted upwardly from a solid stack by the suction cups 110, 112.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a machine for feeding sheets having laterally projecting tabs from the top of a stack, the combination of means for maintaining the top of said stack at a substantially predetermined level disposed below the feed line of said machine, lifting means for raising the topmost sheet in said stack to said feed line, delivery means disposed adjacent said feed line for taking the sheet from said lifting means and moving it edgewise and forward horizontally across the top of said stack to deliver the sheet from said stack, and an upwardly arched flapper finger pivotally mounted adjacent its rearward end in said machine below the top of said stack and rearwardly of a said tab of the topmost sheet in said stack with the upwardly arched front end of said finger biased downwardly toward a protective position overlying said tab and with only the forward tip of said finger in contact with said tab, said finger tip being raised by said tab when said topmost sheet is lifted, and said finger returning downwardly into said protective position over and in finger tip contact with the underlying tab of the next topmost sheet when said tab of the topmost sheet is withdrawn horizontally from beneath said finger tip by said delivery means, in which position said finger prevents interference and interlocking between said protected tab and the tabs on said sheet moving horizontally thereover.

2. The mechanism of claim 1 wherein said flapper finger is thin, narrow and lightweight to facilitate its elevation by relatively lightweight sheets.

3. The mechanism of claim 1 wherein a said arched finger is provided for substantially every one of said laterally projecting tabs on a said sheet.

4. The mechanism of claim 3 wherein said fingers are also mounted for horizontal adjustment to permit accurate positioning of said fingers relative to their respective tabs.

5. The mechanism of claim 1 wherein stop means are provided to hold said finger in substantially said protective position prior to positioning a stack in operative po sition in said machine, and to limit the upward swing of said finger to substantially the level of said feed line.

6'. The mechanism of claim 3 wherein said lifting means comprises magnetic means for separating at least the topmost sheet of the stack and causing it to float upwardly toward said feed line, and wherein said finger tip in its upwardly stopped position resists excessive elevation of the sheet beyond said feed line until said delivery means has control of the sheet.

7. The mechanism of claim 6 wherein said fingers are of non-magnetic material and their pivotal mountings are on horizontal slide bars set into pole pieces of said magnetic means, whereby horizontal adjustment of said igngers may be effected through movement of said slide ars.

References Cited in the file of this patent UNITED STATES PATENTS 648,836 Blaisdell May 1, 1900 696,186 Orlofi Mar. 25, 1902 1,171,011 Young Feb. 8, 1916 1,530,209 Scheuner Mar. 17, 1925 1,742,863 Jurgens et al. Jan. 7, 193.0 1,761,794 Jurgens et al. June 3, 1930 2,156,648 Baker et al. May 2, 1939 2,474,141 Chatterton June 21, 1949 2,797,092 Welsh June 25, 1957 2,799,497 Novick July 16, 1957 2,848,227 Gulick Aug. 19, 1958 

